Gas permeable polymer label for controlled respiration

ABSTRACT

The present document describes a label for installation over an opening of a container to be loaded with produce. The label comprises: a polymer-based film; and micro-perforations through the polymer-based film, whereby upon the polymer-based film being sealingly installed over the opening of the container, the micro-perforations controllably transfer a gaseous substance (such as oxygen and/or carbon dioxide) into or out of the container, through the label, and according to a respiration rate of the produce to be loaded in the container.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of U.S. provisional patent application61/212,120, filed Apr. 8, 2009. For the US only, the foregoing USprovisional patent application is hereby incorporated by reference.

TECHNICAL FIELD

This description relates to packaging for food. More particularly, thepresent specification relates to labels, methods of making such, and thelabelling of containers, to provide gas permeable packaging solutions.

BACKGROUND

The quality and shelf life of fresh produce is enhanced by enclosingthem in packaging that is capable of controlling levels of certain gasessuch as oxygen, carbon dioxide and water vapour (moisture) in theenvironment of the produce.

Such packaging is generally referred to as “Modified AtmospherePackaging” (MAP). Fresher products to the consumer, less waste fromspoiled produce, better inventory control, and appreciable overallsavings for the food industry are only some of the resulting benefits ofMAP.

Typically available produce containers are however not suitable forachieving Modified Atmosphere (MA). For example, typical lid closabletrays made out of rigid plastic material, and which are subsequentlywrapped by a shrink band placed around the lid and tray in order toensure a hermetic sealing of the overall package, do not allow forappropriate gas permeability. Oxygen inside such packaged trays isquickly consumed by the produce stored therein, which leads toaccelerated produce degradation and limited shelf life.

Typical containers, such as the above-noted tray and lid example, arealso typically incapable of providing MA. By Modified Atmosphere (MA),it is intended to refer to the packages ability to modify its interioratmosphere via a controlling of ingress and egress of certain gases.

As produce are known to have characteristic respiration rates undernon-packaged conditions (i.e. the produce's consumption rate of Oxygenand production rate of Carbon Dioxide for example), some gas permeablepackages are specifically designed to be able to provide an optimal MAmeant to slow aging and degradation of a specific produce. Suchspecifically engineered containers are however designed for specifictypes of produce.

As many vendors and/or distributors typically supply a wide variety ofproduce such as fruits, vegetables and meats for example, and thusrequire a number of differently engineered MA containers, there is needfor a packaging solution which offers easy and rapid market penetration;a packaging solution which is adaptable to packaging processes which arealready in place throughout the industry.

SUMMARY

The packaging solution herein disclosed proposes an improved label whichis gas permeable and capable of MA.

The present disclosure seeks to provide an improved label that addressesone or more disadvantages associated with prior art produce packagingand/or labeling, or at least provides useful alternatives thereto.

According to an embodiment, there is provided a label for installationover an opening of a container to be loaded with produce, the labelcomprising: a thin layer of material; and micro-perforations through thelabel, whereby upon the label being sealingly installed over the openingof the container, the micro-perforations controllably transfer a gaseoussubstance into or out of the container, through the label, and accordingto a respiration rate of the produce to be loaded in the container.

According to another embodiment, there is provided a gas permeablepackage comprising: a container for holding produce, the containerdefining an opening to an interior space of the container; a labelsealingly affixed to the container to cover the opening; the labelcomprising a thin layer of material; and micro-perforations practicedtherethrough for controllably transferring a gaseous substance into orout of the container, through the label, and according to a respirationrate of the produce to be loaded in the container.

According to another embodiment, there is provided a method for labelinga container loaded with produce, the method comprising: forming anopening within a container to be loaded with produce; loading theproduce into the container, the produce having a given respiration rate;sealingly installing a label to the container, the label comprising:micro-perforations positioned over the opening once the label adhered tothe container, the micro-perforations for controllably transferring agaseous substance into and out of the container according to therespiration rate of the produce therein.

In the present specification, the term “produce” is intended to refer tofresh fruits and vegetables, flowers, or any other type of produce thatpresents various respiration rates which are to be taken intoconsideration in order to maximize their shelf life.

In the present specification, “shelf life” is intended to refer to thetime until the produce is no longer suitable for consumption and/orpresentation to customers and shall be discarded. In one example, thisis the time until the produce presents fully-ripe or over-ripecharacteristics, whichever the case may be.

In the present specification, “micro-perforations” refer to perforationshaving a well-defined area which allow a controlled transmission ofgases through the package.

In the present specification, the expression “controlled respiration” or“controlled respiration rate” is intended to refer to the control of theamount of gas that is allowed to pass through a material. A sealedcontainer made of such breathable material is able to control the amountof humidity which is allowed to enter and escape from the interiorvolume of the container, while permitting oxygen and carbon dioxide topass through adequately. Produce (also referred to as foodstuff) storedin an interior volume of such a container is able to breathe accordingto a controlled respiration rate; the rate being dependent on a specificdesign of the micro-perforations in the material and which allow suchbreathing to take place. Such a control on the type and the amount ofgazes which are permitted to enter and escape the sealed containersimilarly provides for the control of the internal pressure and humiditylevel inside such containers. The gaseous environment inside the packagemay therefore be kept different compared to an exterior gaseousenvironment (e.g., oxygen levels can be lower inside than outside thepackage, an amount of water molecules can also be kept higher inside thecontainer, and the like).

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present disclosure will becomeapparent from the following detailed description, taken in combinationwith the appended drawings, in which:

FIG. 1 is a schematic front elevation view of a labeled package (e.g., abag), in accordance with an embodiment;

FIG. 2 is a schematic cross-sectional view of the label of FIG. 1;

FIG. 3 a is a method for fabricating the labeled package of FIG. 1, inaccordance with an embodiment;

FIG. 3 b is a method for labeling a container loaded with produce toproduce the labeled package of FIG. 1, in accordance with an embodiment;and

FIG. 4 is a photograph of the labeled package of FIG. 1, with a printedlabel, in accordance with an embodiment.

It will be noted that throughout the appended drawings, like featuresare identified by like reference numerals.

DETAILED DESCRIPTION

There is generally described below, with reference to the appendeddrawings a labeled package 10 comprising a container 12, here in theform of a reclosable bag, for holding fresh produce 16. The bag 12 islabeled with a label 18 in accordance with embodiment as describedherein.

As seen in the embodiment shown in FIG. 1, the bag 12 takes the form ofa closeable recipient which is optionally made of a translucent polymermaterial. The label 18 is in turn made of a polymer material, such aspolyester, and is micro-perforated to provide a controlled respirationrate for the produce 16 stored inside the bag 12. The micro-perforationsof the label are such that the label itself is gas permeable and capableof controlling a respiration through its membrane by way of controllinga type and/or an amount of gas passing there through. In this way, forexample, a moisture level inside the bag 12 is kept constant, whilefurther maintaining an optimal respiration rate for the produce 16.

In the illustrated embodiment of FIG. 1, the bag 12 has an opening 14defining an opening periphery at a location where the label 18 is to bepositioned. The size of the opening 14 is variable and dependent on anoverall size of the bag 12 and/or a size of the label 18 to beinstalled, affixed or adhered. The label 18 is then positioned over theopening 14 such that its adhesive under-coating (not shown) adheres tothe periphery (also referred to as one or more edges) of the opening 14.The label 18 is made to adhere to the container so as to create andairtight, sealed package 10 which is able of gas permeability via thelabel 18 alone.

The label is printable over its exterior or upper surface area 20,although may remain unprinted as desired. In one instance, the area 20has printed information pertaining to the produce 16, a producer, avendor, a price, or any other useful information.

The label 18 is made of various polymer structures, such as any numberor combinations of specific polymer structures suitable for foodcontact: polypropylene, polyethylene or combination of polyethylene andpolypropylene for example. In one embodiment, the label 18 is made of acombination of a paper coated with a plastic layer. The label 18 has athickness varying from about 25 to about 175 microns.

Now referring to FIG. 2, which shows a cross-sectional schematic view ofa specific embodiment of a label 18 with micro-perforations 22.

In the illustrated example, the micro-perforations 22 have a diameter inthe order of about 30 to about 150 microns. In another instance, themicro-perforations 22 have a diameter from about 30 to about 90 micronsin size, whereas in yet another instance, the diameters range from about30 to about 60 microns. In some instances, the distribution of themicro-perforations 22 is uniform over the entire surface of the label18, or an area thereof such as a center or middle-portion. In otherinstances, the micro-perforations are grouped over a specific area ofthe label.

Referring to FIG. 1 and FIG. 2, in one embodiment, the size, position,and distribution of the micro-perforations 22 are dependent on thecharacteristics of the produce 16 and/or of the container 12. Forexample, a respiration rate of the produce 16 as well as a quantity ofproduce 16 in the container 12 is considered. Other characteristicswhich are known to have an incidence on a type and an amount of gastransfer(s) to be allowed and maintained by the label 18 are optionallyconsidered in order to provide an optimal conservation environment forthe produce 16. In this way, the produce's shelf life is extended.

Other non-limiting characteristics which are optionally considered indesigning the micro-perforations include: produce moisture retention,ideal moisture levels, a shape or size of the produce, the container, ora combination thereof. For example, size of one or moremicro-perforations 22 is chosen based on a moisture level to be keptinside the container 12, so as to retain or to allow an escape of watermolecules.

Still in reference to FIG. 2, the label 18 in accordance to theillustrated example has a base layer 24 (also referred to herein as athin layer of material), an optional adhesive layer 26 and an optionalprint layer 28. The print layer can be replaced simply by printing(i.e., printed text or image).

As described above, the base layer 24 is made of a combination ofpolymers or paper-type materials, such as cardboard or wax paper, coatedwith polymer. Materials for the base layer 24 can also includetranslucent plastics, cellulose-based films and corn-based films aloneor in combination.

In the illustrated embodiment, the adhesive layer 26 is provided as anunder-coating, or on a reverse side of the label 18 intended to beadhered to a container. In one embodiment, the adhesive layer is of apermanent type, although kept suitable for food contact and ingestion.In another embodiment, the adhesive layer is non-permanent to allowremoval and re-adherence. Such a label is usable to open the containervia the opening to access the produce therein. In such an embodiment thelabel 18 in fact could replace the lid (or cover) entirely.

It is noted that the adhesive layer 26 is optional when the adhesive isprovided on the container 12 instead; e.g., in the periphery of opening14.

In addition, in a particular example, the adhesive layer 26 of the label18 is provided adjacent the print layer 28, both applied on a same sideof the base layer 24. This embodiment is used in cases where the labelis affixed to the container via adherence on an interior wall of thecontainer, as later described.

Non-limiting examples of adhesives which can be used include eitherwater or solvent based adhesives; acrylic or rubber emulsions such assoluble rubber or maleic anhydride (MAH) adhesives for example, whichare permanent or not; or any food-grade approved adhesive compositions,glues or epoxies which are adapted to adhere to a variety of surfacessuch as paper, corrugate, metals, glass, vinyl, foam, fabric,polystyrene, polypropylene, polyethylene, paper, or corrugate underwhichever conditions such as cold, hot, damp or dry conditions. In oneembodiment for example, the adhesive layer is a transparent, non-tackyand flexible film composition such as a vinyl acetate-maleate copolymerresin available on the market as a blend of isopropyl acetate andtoluene.

Other means of installing the label are also contemplated. Examplesinclude any type of airtight seal. Examples of such airtight sealsinclude the zipper lock type closures which are commonly found onplastic food bag. Of course, a combination of any of the installationschemes described herein would also be feasible.

The print layer 28 is present when the label 18 is printed with a layerof ink suitable for proper adherence to the upper or front side of thelabel 18 opposite the adhesive layer 26. Any inks which are suitable forprinting on a polymer-based material such as any suitable food-safe inksare used.

In one embodiment, the label 18 is a self-adhesive permanent label 18 inthat the adhesive layer 26 does not require the application of extramoisture in order to obtain an adhesive effect of the layer. In oneexample, once applied, such an adhesive layer 26 is protected with abacking paper (not shown) until it is removed prior to sticking thelabel 18 on the container 12.

Still in reference to FIG. 2, it is noted that an additive compound 29is optionally added to the base layer 24. The additive compound 29 canadditionally or alternatively be added to the adhesive layer 26. Such anadditive compound 29 is intended to be used for example, to provide acontrol on a ripening rate of the produce stored in the container, or toimprove translucence of the container by controlling any fogging effectoccurring from the moisture level inside the container. Non-limitingexamples of additives which are optionally used include food gradeanti-fog agents and ripening agents such as food grade ethyleneabsorption additives.

The label 18 is fabricated according to any type of suitablemanufacturing method such as one illustrated in FIG. 3 a. In thisexample, the method 30 involves the following steps:

In step 32, an adhesive layer is applied over a thin layer of materialin order to form a label substrate. This step is accomplished in oneexample by coating at least one side of a sheet of film material formingthe base layer with a layer of adhesive substance. The other side or thesame side is optionally printed by way of applying a print layer.

Then, in step 34, at least a portion of the label substrate ismicro-perforated to provide micro-perforations through the labelsubstrate, which includes the base layer, the adhesive layer and theprint layer when applied in step 32. The micro-perforations are designedin size and distribution over the label substrate so as to controllablytransfer on ore more given gaseous substances through the labelsubstrate, and based on the respiration rate of the fresh produce to becontained in the container. For example, the micro-perforations have asize which is able to allow the ingress of oxygen while venting outcarbon dioxide and retaining moisture inside in accordance to theproduce's needs for longer shelf life.

In one embodiment of step 34, the label substrate is micro-perforatedaccording to a pre-established design, by subjecting the label substrateto a number of small high voltage electric discharges (intense energeticsparks) which vaporize the substrate at their application location. Inanother example, a laser is used to produce the micro-perforations.

In step 36, the label substrate is cut to form one or more gas permeablelabels in accordance with a final size and shape. While this step isoptionally done prior to step 32 and/or 34, in this embodiment, thelabel substrate is cut to provide one or more finished self-adhesivelabels. Alternatively, cut lines are created in order to supply sheetsof multiple pre-formed labels and allow produce distributors tothemselves cut and separate the labels from one another.

Alternatively, the above method 30 is varied such that the base layer ismicro-perforated (step 34) prior to the coating of the adhesive andoptional print layer (step 32). In such a variation, the layeringtechnique used to apply the adhesive layer and the optional print layeron the base layer does not reclose the micro-perforations. For example,the type of adhesive and the ink used are composed of small enoughparticles which eliminate any risks of clogging micro-perforations.

Additionally or alternatively, in one embodiment, the adhesive layer isapplied over a given area of the label, while the micro-perforated areaoccupies another area of the label different than the given area used bythe adhesive layer.

In a similar fashion, in one instance where both the adhesive layer andthe print layer are applied over a same side of the base layer in step32, the adhesive layer is applied over a given area of the label whichis different than the area occupied by the print label. For example, theadhesive layer is positioned along a periphery of the label, while theprint layer is at a middle-portion of the label.

In the above method 30, it is noted that the application of the adhesivelayer in step 32 is optional when for example the adhesive is to beinstead applied on the container prior or during the affixing the labelthereon.

In addition, in some cases, the final cutting step 36 is performed priorto the printing of the label (application of the optional print layer).

The final label is capable of maintaining a given respiration rate inaccordance to the sizes and shapes of the micro-perforations.

Now referring to FIG. 3 b, there is shown a method 40 for labeling acontainer which is to be or is previously loaded with produce.

In step 42, an opening is formed within a container (or a lid portionthereof) which is to be loaded with produce.

In step 44, the produce is loaded into the container. The produce can beany produce which has a given pre-established respiration rate, or rangeof thereof, as known from the type of quantity of produce stored in thecontainer.

In step 46, the gas permeable label is fixedly and sealingly positionedonto the container, over the opening. The gas permeable label has anadhesive film which is meant to adhere along the periphery of theopening in order to provide for an airtight seal with the container. Inthis way, the overall package respires from the label. This is possiblesince the micro-perforations are provided through the adhesive film at alocation on the film which is in-line or at least corresponding to alocation of the opening once the gas permeable label is positioned ontothe container.

In one embodiment, the adhesive film of the label is such that in step46, a slight pressure is applied on the label to affix it to thecontainer.

The micro-perforations allow for the label to controllably transfer oneor more gaseous substances into and out of the container in order tomaintain a given gaseous environment inside the container, as providedfrom the respiration rate of the produce.

In an example, the label has an adhesive layer for allowing the label tobe adhered along a periphery of the opening.

FIG. 4 is a photograph of the package 10 of FIG. 1, with the label 18being printed with package information such as: a description of theproduce 16 inside the container 12; a purchasing price; a vendor's name;a bar code associated to the package; and the like.

In this example, the produce 16 comprises a mix of cut and washedvegetables including carrots and baby tomatoes. Any other produce canhowever be packaged, such as any vegetable, fruit, meat, fish, nuts,baked goods, and the like.

The gas permeable, micro-perforated label 18 as per the abovedescription is positioned over the opening 14, which is here circularand formed on a top surface of the container 12. In one embodiment, thesize of the opening 14 is such as to create an opening area betweenabout 150 mm² and 600 mm². In another embodiment, the size of theopening 14 has an opening area between about 600 mm² and 1000 mm². Thesize of the opening 14 is however adjustable and dependent on thecontainer's shape and size, as well as the quantity and/or type ofproduce 16 therein.

In one embodiment, the label 18 is affixed from an interior side of thecontainer 12. For example, the container 12 in the picture of FIG. 4 hasa lid 50 onto which is located the opening 14. The label 18 is affixedfrom the interior side of the lid 50 using adhesive located between thelabel and the periphery of the opening 14. In this way, the container isloadable with produce after the installation of the label thereto, butprior to the closing of the lid 50.

Although shown as a rigid clam shell tray container with the foldablelid 50, the container 12 can be any type of container such as a bag madeof plastic-type material or a differently shaped container such as abottle, a box, or any other hollow interior recipient for storingproduce, not necessarily re-closable or re-sealable.

While preferred embodiments have been described above and illustrated inthe accompanying drawings, it will be evident to those skilled in theart that modifications may be made therein without departing from thescope of this disclosure. Such modifications are considered as possiblevariants comprised in the scope of the disclosure.

1. A label for installation over an opening of a container to be loadedwith produce, the label comprising: a thin layer of material; andmicro-perforations through the thin layer of material, whereby upon thelabel being sealingly installed over the opening of the container, themicro-perforations controllably transfer a gaseous substance into or outof the container, through the label, and according to a respiration rateof the produce to be loaded in the container.
 2. The label of claim 1,wherein the thin layer of material comprises at least one of apolymer-based film, a layer of translucent plastic, a layer ofpaper-based material a cellulose-based film, and a corn-based film. 3.The label of claim 1, comprising printing on at least a portion of thethin layer of material, the print layer for providing labelinginformation.
 4. The label of claim 1, comprising a layer of adhesiveover at least a portion of the thin layer of material.
 5. The label ofclaim 1, comprising an additive in any one of the layers of the label.6. The label of claim 1, wherein the label has a thickness from about 25to about 175 microns.
 7. The label of claim 1, wherein themicro-perforations have a diameter from about 30 to about 150 microns.8. The label of claim 6, wherein the diameter is from about 30 to about90 microns.
 9. The label of claim 6, wherein the diameter is from about30 to about 60 microns.
 10. The label of claim 1, wherein themicro-perforations are uniformly distributed over a middle-portion areaof the label.
 11. The label of claim 10, wherein the additive comprisesat least one of: an ethylene absorption agent for slowing a ripeningrate of the produce to be stored in the container; and an anti-fog agentfor improving a translucence of the container once labelled.
 12. A gaspermeable package comprising: a container for holding produce, thecontainer defining an opening to an interior space of the container; alabel sealingly affixed to the container to cover the opening; the labelcomprising a thin layer of material; and micro-perforations practicedtherethrough for controllably transferring a gaseous substance into orout of the container, through the label, and according to a respirationrate of the produce to be loaded in the container.
 13. The gas permeablepackage of claim 12, wherein the thin layer of material comprises atleast one of a polymer-based film, a layer of translucent plastic, alayer of paper-based material a cellulose-based film, and a corn-basedfilm.
 14. The gas permeable package of claim 12, wherein the containercomprises a lid and the opening is defined in the lid.
 15. The gaspermeable package of claim 12, further comprising an adhesive foraffixing the label to the container.
 16. The gas permeable package ofclaim 15, wherein the label comprises the adhesive.
 17. The gaspermeable package of claim 16, comprising an additive in any one of thelayers of the label.
 18. The gas permeable package of claim 12, whereinthe label is printed portion on at least a portion of the thin layer ofmaterial, to provide labeling information.
 19. The gas permeable packageof claim 12, wherein the label has a thickness from about 25 to about175 microns.
 20. The gas permeable package of claim 12, wherein themicro-perforations have a diameter from about 30 to about 60 microns.21. The gas permeable package of claim 12, wherein themicro-perforations are uniformly distributed over a middle-portion areaof the label.
 22. The gas permeable package of claim 12, wherein thecontainer comprises at least one of a bag, a box, and a closeablebowl-like container.
 23. A method for labeling a container loaded withproduce, the method comprising: forming an opening within a container tobe loaded with produce; loading the produce into the container, theproduce having a given respiration rate; sealingly installing a label tothe container, the label comprising: micro-perforations positioned overthe opening once the label adhered to the container, themicro-perforations for controllably transferring a gaseous substanceinto and out of the container according to the respiration rate of theproduce therein.